function [x,y] = plot_period(data_file, linestyle, period)
    a = load(data_file);
    x = zeros(period+1,1);
    y = x;
    for i=0:period
        n = find( a(:,2) >= i , 1, 'first');
        x(i+1) = a(n,5);
        y(i+1) = a(n,2);
    end
    semilogx(x,y,linestyle,'LineWidth',2); hold on
    %loglog(x,y,linestyle,'LineWidth',2); hold on
end